In the context of 9 attainments (4 jhāna, 4 immaterial states, cessation of perception & feeling) why jhāna isn’t called āyatana? Why only the “immaterial” attainments ( ākāsānañcāyatana, viññāṇañcāyatana, ākiñcaññāyatana, nevasaññānāsaññāyatana) are called āyatana? Is there a special significance in that?
The significance is that the ‘ayatana’ secondary meaning is the sense spheres and these are overcome in the immaterial attainments.
If one overcomes āyatana in immaterial attainments, then why call those states x-āyatana?
Why not call jhānas to be āyatana instead?
Your sense experience (āyatana) is of one thing (Infinite Space etc). So, if we take the first one, all you see is “space” instead of space and forms.
In contrast to Western materialism, in the Buddhist perspective ‘non-action’ is the positive quality. So ‘ayatana’ the absence of the form realm is the desirable reality, like anatta. The results of non-action can be seen with the observation of cause & effect.